The cheongsam is a sheath dress with a high cylindrical collar, side slits and an asymmetrical opening in the front that stretches from the middle of the collar to the armpit and down the side. The opening is traditionally secured with knotted buttons and loops known as hua niu (flower button).

The cheongsam is believed to have evolved from a long robe worn by Manchu women during the Qing dynasty (1644–1911) in China. The long gown was cut in a single piece that hung straight down to the ankles. There was a slit on either side of the gown but other garments worn underneath prevented the legs from showing.

Prior to the cheongsam, Chinese women generally wore two-piece outfits consisting of tops paired with either skirts or pants. The cheongsam was not immediately popular due to its resemblance to the men’s one-piece gown known as the changshan (long shirt) or changpao (long robe).

The earliest cheongsams were loosely fitted and had a low hemline that reached the ankles. A group of female students in Shanghai became one of the first women to wear the cheongsam when they started donning the outfit in 1912. The cheongsam first became popular in late 1920s Shanghai, which was then an influential fashion capital. The cheongsam spread from Shanghai to places with large Chinese communities such as Hong Kong, Taiwan and Singapore. Shanghai calendar posters that featured beautiful women dressed in cheongsams also helped to boost the popularity of the dress.

Cheongsams can be made using a variety of materials to suit various seasons, occasions and budgets. Materials used for making cheongsams include satin, silk, brocade, velvet, lace, and cotton. Cheongsams for daytime wear are normally simple in design with only piping and prints for decoration. Evening wear cheongsams have far more elaborate designs and are usually adorned with sequins and beads. For work, the cheongsam is sometimes paired with a matching Western-style jacket.

The lengths of the hems and sleeves of the cheongsam have changed with fashion trends, although the fit of the dress has generally become tighter over the years. The trend towards closer-fitting clothes that show the wearer’s figure reflects the growing influence of Western values among Chinese women. For the best fit, most cheongsams were traditionally custom-made for the wearer. Shanghainese tailors in particular were renowned for their skill in making cheongsams.

According to eresources.nlb.gov.sg